find if an integer exists in a list of integers

akantro_4653 0
Viewed 222555

i have this code:

  List<T> apps = getApps();

        List<int> ids;

        List<SelectListItem> dropdown = apps.ConvertAll(c => new SelectListItem
        {
            Selected = ids.Contains(c.Id),
            Text = c.Name,
            Value = c.Id.ToString()
        }).ToList();


ids.Contains

seems to always return false even though the numbers do match

any ideas?

integer arrays c#
8 Answers

The best of code and complete is here:

NumbersList.Exists(p => p.Equals(Input)

Use:

List<int> NumbersList = new List<int>();
private void button1_Click(object sender, EventArgs e)
{
    int Input = Convert.ToInt32(textBox1.Text);
    if (!NumbersList.Exists(p => p.Equals(Input)))
    {
       NumbersList.Add(Input);
    }
    else
    {
        MessageBox.Show("The number entered is in the list","Error");
    }
}
user_83002560 
string name= "abc";
IList<string> strList = new List<string>() { "abc",  "def", "ghi", "jkl", "mno" };
if (strList.Contains(name))
{
  Console.WriteLine("Got It");
}

/////////////////   OR ////////////////////////

IList<int> num = new List<int>();
num.Add(10);
num.Add(20);
num.Add(30);
num.Add(40);

Console.WriteLine(num.Count);   // to count the total numbers in the list

if(num.Contains(20)) {
    Console.WriteLine("Got It");    // if condition to find the number from list
}
user_109536240
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